Harnessing the quantum properties of single-electron wave packets for quantum metrology has been the goal of the European EMPIR research project SEQUOIA (17FUN04). This encompassed the further development of concepts and theoretical methods of electron quantum optics as well as the development of new experimental methods and techniques for and demonstrations of single-electron-based quantum metrology. This white paper provides an educational introduction into the state-of-the-art theoretical concepts and methods of electron quantum optics as the foundation for single-electron wave packet quantum metrology. Furthermore, it showcases new techniques and applications, to be used in and to inspire both basic research and quantum metrology and technology applications.,EMPIR projects are co-funded by the European Union’s (EU) Horizon 2020 research and innovation programme and the EMPIR participating states.,

2022